G-SYNC 101: External FPS Limiter HOWTO


In-game vs. External Framerate Limiters*

*As of Nvidia driver version 441.87, Nvidia has made an official framerate limiting method available in the NVCP; labeled “Max Frame Rate,” it is a CPU-level FPS limiter, and as such, is comparable to the RTSS framerate limiter in both frametime performance and added delay. The “Nvidia Inspector: 2> Frame Delay” setup detailed further below is legacy, and does not apply to the “Max Frame Rate” limiter, the setup of which is also now detailed below it.

As described in G-SYNC 101: In-game vs. External FPS Limiters, In-game framerate limiters, being at the game’s engine-level, are almost always free of additional latency, as they can regulate frames at the source. External framerate limiters, on the other hand, must intercept frames further down the rendering chain, which can result in delayed frame delivery and additional input lag; how much depends on the limiter and its implementation.

In-game framerate limiters, however, aren’t available in every game, and while they aren’t required for games where the framerate can’t meet or exceed the maximum refresh rate, if the system can sustain the framerate above the refresh rate, and a said option isn’t present, an external framerate limiter must be used with G-SYNC to prevent V-SYNC-level input lag instead.

RTSS is a CPU-level FPS limiter, and introduces up to 1 frame of delay, whereas Nvidia Inspector uses a driver-level FPS limiter, which introduces 2 or more frames of delay. See G-SYNC 101: In-game vs. External FPS Limiters for complete details, along with input latency tests comparing the two external solutions against an in-game limiter.

RivaTuner Statistic Server: <1 Frame Delay

RTSS is available standalone here, or bundled with MSI Afterburner here.

If only a framerate limiter is required, the standalone download will suffice. MSI Afterburner itself is an excellent overclocking tool that can be used in conjunction with RTSS to inject an in-game overlay with multiple customizable performance readouts.

Blur Buster's G-SYNC 101: External FPS Limiter HOWTO

RTSS can limit the framerate either globally or per profile. To add a profile, click the “Add” button in the lower left corner of the RTSS windows and navigate to the exe. To set a frame limit, click the “Framerate limit” box and input a number.

Nvidia Inspector: 2> Frame Delay

An unofficial extension of the official Nvidia Control Panel, Nvidia Inspector (download here) exposes many useful options the official control panel does not, including a driver-level framerate limiter.

Nvidia Inspector can limit the framerate either globally or per profile (more details on profile creation can be found here).

To set a frame limit, locate the “Frame Rate Limiter” dropdown in the “2 – Sync and Refresh” section, select the desired limit, and then click the “Apply Changes” button in the upper right corner of the Nvidia Inspector window.

Blur Buster's G-SYNC 101: External FPS Limiter HOWTO

As of Nvidia Profile Inspector version 2.1.3.6 and Nvidia driver branch R381 or later, a new “Frame Rate Limiter Mode” dropdown has been introduced with a “Limiter V2 – Force Off” option:

Blur Buster's G-SYNC 101: External FPS Limiter HOWTO

This option claims to reduce the limiter’s input lag; exactly by how much, and with what combination of settings, remains to be determined.

NVIDIA Control Panel: <1 Frame Delay

As of Nvidia driver version 441.87, Nvidia has made an official framerate limiting method available in the NVIDIA Control panel labeled “Max Frame Rate.”

To set a framerate limit, navigate to the “Manage 3D settings” section in the NVCP, locate the “Max Frame Rate,” entry, select “On,” set the desired limit, select “OK,” and finally select the “Apply” button after it appears in the lower right corner of the NVCP window.



3569 Comments For “G-SYNC 101”

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fighter7777777
Member
fighter7777777

Hello, does this guide also apply to intel users as well? Such as if Intel’s XELL mode behaves differently to NVidia’s reflex and recommendations vary for intel.

pmanha
Member
pmanha

RTSS Framelimiter: stick with async (default) or change it?

So I’ve been messing around with FPS caps and I’m kinda torn. I saw a post on reddit saying RTSS Framelimiter async introduces more latency compared to Reflex, which got me thinking…

Right now I can either:

Use Reflex and cap at 225fps

Use RTSS Framelimiter (async) and get ~236fps

Is that tiny FPS gain really worth the potential input lag?

Hannibal0098
Member
Hannibal0098

Interesting take on VSync with FPS limiter, I have tried this before (limiting my FPS to 59 on a 60hz monitor with VSync) but I never experienced the stutter mentioned. Maybe it varies from game to game? I haven’t tried this on Overwatch.

anthony3192
Member
anthony3192

How do I know that in no reflex games I’m getting as little input lag as possible? It almost seems that when I activate gsync + vsync from NVCP the input lag is much higher than when I only have gsync active. Obviously I’m talking to you about titles without reflex.

tomatojuice
Member
tomatojuice

I see that this article was published in 2017 and I am not sure if it’s been updated so I wanna ask a few questions.You advise FreeSync folks to use in-game V-SYNC as “AMD control panel V-SYNC is limited to OpenGL”.Is this still the case?

Also AMD adrenaline software has Radeon Enhanced Sync and VSync, which one should one use?

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